Consolidated Statements Of Condition (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Held-to-maturity securities, at Fair value	$ 807,036	$ 607,602	$ 942,666
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000	20,000,000
Common stock, $1.00 stated value (usd per share)	$ 1.00	$ 1.00	$ 1.00
Common stock, 100,000,000 shares authorized (in shares)	100,000,000	100,000,000	100,000,000
Common stock, shares issued (in shares)	55,939,801	51,978,289	51,811,204
Treasury stock, (in shares)	101,738	97,749	96,521
Series C Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 1,000	$ 1,000	$ 1,000
Preferred stock, shares outstanding (in shares)	0	126,257	126,257
Series D Preferred Stock
Preferred stock, liquidation value per share (usd per share)	$ 25	$ 25	$ 25
Preferred stock, shares outstanding (in shares)	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	5,000,000	5,000,000	5,000,000